HGH doses and usage

Before I go any further I just to say I am asking for this information beacause a friend of a friend has got hold of some hgh powder from China and hasnt got a clue (nor do I which is why I aint gonna mess with stuff I dont understand) and I wouldnt want any harm to come to him. First off all I am told he has 1.6mg (4iu) vials and wants to know the ratio of water to mix it with. And then also about dosage. If anyone knows any information that could help please let me know.